Method for producing film

A method for producing a film, the method comprising:

• pattern-coating a slurry on a metal substrate, wherein the metal substrate has a thermal conductivity of about 8 Watts per meter per Kelvin (W/mK) or more;
• drying the pattern-coated slurry before sintering the pattern-coated slurry, wherein drying the pattern-coated slurry is performed at a temperature in a range of from 120° C. to 150° C.;
• and
• sintering the pattern-coated slurry to form a porous metal layer on the metal substrate to thereby produce the film that includes the metal substrate and the porous metal layer,
• wherein the slurry comprises thermally conductive metal particles, a binder, and an alcohol,
• wherein the metal substrate is the same material as the thermally conductive metal particles in the slurry,
• wherein sintering the pattern-coated slurry is performed at a temperature in a range of from 300° C. to 1100° C. in an atmosphere including hydrogen and argon,
• wherein the alcohol is texanol and/or terpineol,
• wherein the slurry comprises the alcohol in an amount of 160 to 500 parts by weight relative to 100 parts by weight of the thermally conductive metal particles,
• wherein the porous metal layer has a porosity of 70% or more, and
• wherein the porous metal layer has a thickness of 150 μm or less.